Low Form Dip Spin Coating / High Dipping Speed Electroplated Zinc
Coating
Dacromet anti-corrosion coating characteristics
1.1 anti-corrosion mechanism Dacromet coating, the appearance of
matte silver gray, from the very fine sheet metal zinc, aluminum
and chromate and other ingredients. After the workpiece in the
degreasing, shot blasting treatment, dip Tu Duo Luo liquid.
Dacromet liquid is a water-based treatment solution, metal parts in
the water-based treatment solution dip or spray, and then into the
furnace curing, about 300 ℃ baking film, and the formation of zinc,
aluminum, chromium inorganic coating Floor.
2. Coating Process
Mix Ratio
Pack A:16.0 kg
Pack B:24.0 kg (the quantity can be increased appropriately if
spray coating)
Pack C:0-50 g (according to different viscosity demand )
3
Mixture Method |
Before Mixture, Keep weighted A&B into the water bath at 25±2℃
, then stir A to make metal slurry disperse uniformly by frequency
mixer ,after A is fully evenly dispersed, reduce the agitating
speed to 60r/min, and add B.
3.2.2 |
Add B to the stirring A slowly. At the moment ,the barrel
temperature will go up,when it reaches 35℃, startup refrigerating
device to keep the barrel temperature constant at 35℃. |
4. Technical data
| No. | Item | Data |
| 1 | PH | 3.8-5.2 |
| 2 | Cr6+ | ≥25g/L |
| 3 | Specific gravity | 1.30±0.05 |
| 4 | Viscosity | 20~60s(Spray Coating) ; 60~90S(Dip-Spin Coating) . 20℃ Zahn 2# cup |
| 5 | Operating temperature | 22±2℃ |
5. Coating Process
6.1 Degreasing
The workpiece should be degreased if there is oil on the surface.
There are three processing methods:
1.High temperature
2.Neutral water-base degreasing agent
3.Organic solvent such as methylene chloride.
6.2 Derusting
The workpiece can not be coated if there is rust or burr on the
surface.The best processing method is shot blasting. The corrosion
resistance of coating will be effected if acid cleaning adopted.
6.3 Coating
The workpiece afer degreasing and shot blasting should be coated
through Dip-Spin coating or Spraying Coating.
6.4 Pre-heating
The workpiece after coated should be Pre-heated as soon as possible
at 80~150℃ for 8~15 mins to evaporate. ( according to heat
absorption of workpiece.)
6.5 Curing
The workpiece after pre-heating should be cured at 300-340℃ for
20-40 mins. ( according to heat absorption of workpiece.)
